The present invention relates to optical systems having a corrective wedge prism to provide improved control over light reflectivity.
A number of optical elements use total internal reflection (TIR) for controlling the movement of light. Example optical elements having a TIR surface include prisms, Fresnel structures, and conic structures. In general, a relationship exists between the area of the TIR surface and the emission area of its nearby light source. As the area of TIR surface relative to the emission area of the light source decreases, the likelihood of losing energy through the TIR surface increases. Consequently, optical systems that use light sources having a large emission area can be prone to undesired efficiency losses. While optical coatings on key surfaces (reflectors or TIR surfaces) are suitable in some applications to limit efficiency losses, optical coatings may not be possible in all applications. For example, manufacturing costs and material incompatibilities can prevent the use of optical coatings in some applications.
It would therefore be beneficial to provide an improved optical system which reduces light losses through TIR surfaces while generating a more efficient light distribution across an illuminated area. In particular, it would be beneficial to provide a more efficient light distribution in conjunction with extended source light emitting elements, including for example one or more light emitting diodes (LEDs).